Apparatus and method for removing arsenic and inorganic compositions from water

Abstract

Simultaneous application of ozone and ultraviolet light (UV185 and UV254) in water to be purified will create hydroxyl radicals, which combination will cause conversion of AS (III) that may be present to As (V), oxidation of inorganic matter such as manganese, sulfur, phosphorus and organic matter and provide virucidal and germicidal effects to purify the water.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThe present invention relates to the removal of arsenic, iron, phosphorus, sulfur, manganese and other dissolved minerals, whether naturally occurring or byproducts of commercial activities and, more particularly, to conversion of arsenic to arsenate and oxidation of other organic and inorganic matter.2. Description of Related Prior ArtArsenic occurs naturally in the environment as a heavy metal in two different forms, arsenite [As (III)] and arsenate [As (V)]. Arsenic is released into water supplies from erosion of rocks and soil. The distribution of arsenic in soil, ground water and surface water has extensively been investigated during the past two decades.Long term exposure is proven to result in health effects, such as cancer, cardiovascular disease, diabetes and reproductive problems. Nationally, about three thousand or 5.5% of the nation's 54,000 community water systems and 1,100 (or 5.5%) of the twenty thousand non-transien...

AI Technical Summary

Benefits of technology

The present invention relates to the discovery that simultaneous application of ultraviolet light (UV) and ozone (with optional addition of hydrogen peroxide) during treatment of water containing arsenic will effectively convert As (III) to As (V) even in the presence of sulfides and organic matter. This result was unexpected as UV radiation is ineffective to convert As (III) to As (V) and as independent studies indicate that in the presence of sulfides and organic matter the oxidizing ability of ozone is suppressed. It is believed that the formation of hydroxyl radicals resulting from the interaction of UV and ozone may be less discriminating and less affected by the presence of other impurities such as sulfides and organic matter and thereby accomplish the conversion of As (III) to As (V). Moreover, the dual use of UV and ozone that produce hydroxyl radicals that bring about oxidation of other inorganic matter, such as manganese, sulfur, phosphorus and organic matter.

Yet another object of the present invention is to provide a relatively inexpensive apparatus for converting As (III) to As (V).

Problems solved by technology

Long term exposure is proven to result in health effects, such as cancer, cardiovascular disease, diabetes and reproductive problems.

Short term exposure to high doses of arsenic can cause other adverse health effects, but such effects are unlikely to occur from U.S. public water supplies that are in compliance with the arsenic standard.

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